Atomic

iTrader: (42)

Yes, extensive work by Gilbert to fix the not locking in 4th issue. It isnt the same type of problem you are talking about, but I think I got it figured out.

I read something on the hptuners forum about the speedo being off causing this type of error, so I double checked my vss pulses and corrected it and the speedo is dead-nuts on for what it should be with the tire height and gear ratios. However, there is still a ~150rpm slip when its "locked", but the math isnt showing that... Remembering I am still using the 60e tune, I checked the numbers with the 60es deeper OD and sure enough, that would make the "TCC Slip" equal to about 0. What this implies is the PCM has knowledge of the gear ratios in the transmissions and doesnt just use the speed sensors to calculate it.

Case in point;
I logged engine rpm, input shaft rpm, output shaft rpm, and tcc slip in a steady state highway situation. For this particular case these were the values:

Engine - 2212
Input - 2052
Output - 2953

So "TCC Slip" is defined as the difference between the engine rpm and input shaft rpm, so in this case it is measured as 2212-2052=160, which is exactly what HPT showed. But lets keep in mind where these numbers come from. The physical sensors are on the engine (crank sensor) and output shaft (vss sensor), so where does that input rpm number come from? Took me a while to figure out that it is a calculated value...based on the transmission ratios, and as far as the PCM knows im still using a 60e, not an 80e. So lets repeat the exercise for TCC Slip accounting for the correct ratios and knowledge that the physical sensors are accurate (engine and output).
[2212-(2953*.75)] = 0 That is to say the engine speed minus the trans output speed times the OD ratio I actually have gives me the true input rpm and now produces a TCC Slip value of 0 rpm. Excellent.

I am relieved to finally have an answer I am happy with, but disappointed there isnt a way to fix the problem without doing a segment swap as there is not access to the gears the PCM assumes you have. I dont want to do the segment swap because the torque converter unlocking at 0% throttle is extremely annoying. Secondly, if I am in a condition where the clutch is engaged, its at high speeds, so if I let off the gas I want the additional engine braking.

If you are particularly interested in seeing the TCC Slip value making a custom PID to get the *true* TCC slip is not hard, it would simply be:
[engine rpm] -[trans_output_shaft_rpm*.75] = TCC Slip
However, if you wanted the slip in every gear, you would need to make 4 pids based on the 80e ratios for 1st through 4th (2.48, 1.48, 1, .75). The above case only works in 4th gear.
I was mainly concerned with this because I thought there was a legitimate hardware problem, which I didnt want cooking my clutches and ultimately destroying an expensive drivetrain.

oldred95

Yea the transmission gear ratios are incorporated into the tuning so it knows whats what and uses it for various calculations as you found out. I hadn't thought about it throwing off your slip speed calculation like that but I was thinking my setup where copying over the gear ratio table from the 80E to a 60E was just part of the process.

See this is what I hate so much about EFI live. You pay 800 bucks for it and you can't do **** with it. Changing the shift solenoid state table and gear ratio tables is easy easy stuff but as far as I know its not allowed hence the reason you guys get stuck using a damn relay on a 60E code.

Petey62782

iTrader: (19)

What's also weird is I have a very similar problem with my built Trans and when I spoke directly to tech support at Transgo he said that the slip is completely normal as of the transgo HD2 . I get about a 200 rpm slip with my TCC after I goto re-engage the throttle after coast

Atomic

iTrader: (42)

I got your pm, but Ill respond in here.

Im pretty sure Gilbert used parts from different kits in my particular valve body, so I dont think the transgo issue is relevant to me. I am confident my above post about the gear ratios in the pcm is correct. If not, its one hell of a coincidence that the math works out. Are you running an 80e with a 60e tune and relay? I believe this issue is specific to that, so if you are using a 60e or an 80e with a segment swap and still have this problem, you may have a hardware issue.

What are your: engine rpm, input shaft rpm, and output shaft rpm?

Petey62782

iTrader: (19)

I'm going to data log those rpm speed tomorrow and I have a FLT 4L65 with a yank 2600. Yeah sorry atomic I thought that the valve body kit might help ya but I geuss ur is a little different .

joeyc125

iTrader: (7)

I also had the same problem with the lockup. I put 5k miles on it and it seemed fine, lockup at part throttle felt good, scanner always showed a little slip but I thought it was an error. I tried tuning for wot lockup the night before I went to the dyno and noticed a little slip when the boost would hit. Went to the dyno, completely smoked the tc clutches in my billet circle d converter. Ended up being the same thing oldred95 mentioned, the tcc valve bore needed to be honed/bored. My trans guy took care of it. Works perfect now, wot lockup almost feels too hard, might take a hair out of the min/max table.

joeyc125

iTrader: (7)

Btw, this was a fresh rebuilt trans from a reputable builder. He said it seemed to check out the first time, and this was the first one he saw with this issue. But he thought I was the only one with big power that locks the converter under wot at full boost. He has been around for years in the performance trans business and has 3-4 dozen high hp (750-1300) 4l80's running around the Midwest.

oldred95

What is the reason for running the 80E on the 60E tune if you can't properly adjust the necessary tables? The relay method does work, I did it for a while, but I hated the added delay I got from it. My 80E was always slow to downshift but the relay made it a touch slower yet.

Atomic

iTrader: (42)

Because using the 80e segment makes the converter unlock at 0% throttle, which I find very annoying

oldred95

So I'm going through the tune I'm going to be using on my new engine setup and came across the gear ratio values. Take a look at D1201-D1204. Try setting those to the 80E's ratios if you haven't and see if your slip speed doesn't read right. Don't forget to change the Shift Stabilization Ratios under the General tab under the transmission calibration category.